linux/arch/m68k/platform/coldfire/entry.S
Greg Ungerer f941f5caa0 m68k: merge MMU and non MMU versions of system.h
The non-MMU m68k targets can use the same asm/system.h as the MMU
targets. So switch the current system_mm.h to be system.h and remove
system_no.h.

The assembly support code for the non-MMU resume functions needs to
be modified to match the now common switch_to() macro. Specifically
this means correctly saving and restoring the status flags in the case
of the ColdFire resume, and some reordering of the code to not use
registers before they are saved or after they are restored.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-07-25 11:20:40 +10:00

205 lines
5.2 KiB
ArmAsm

/*
* linux/arch/m68knommu/platform/5307/entry.S
*
* Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
* Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
* Kenneth Albanowski <kjahds@kjahds.com>,
* Copyright (C) 2000 Lineo Inc. (www.lineo.com)
* Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com)
*
* Based on:
*
* linux/arch/m68k/kernel/entry.S
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file README.legal in the main directory of this archive
* for more details.
*
* Linux/m68k support by Hamish Macdonald
*
* 68060 fixes by Jesper Skov
* ColdFire support by Greg Ungerer (gerg@snapgear.com)
* 5307 fixes by David W. Miller
* linux 2.4 support David McCullough <davidm@snapgear.com>
* Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be>
*/
#include <linux/linkage.h>
#include <asm/unistd.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
#ifdef CONFIG_COLDFIRE_SW_A7
/*
* Define software copies of the supervisor and user stack pointers.
*/
.bss
sw_ksp:
.long 0
sw_usp:
.long 0
#endif /* CONFIG_COLDFIRE_SW_A7 */
.text
.globl system_call
.globl resume
.globl ret_from_exception
.globl ret_from_signal
.globl sys_call_table
.globl inthandler
.globl fasthandler
enosys:
mov.l #sys_ni_syscall,%d3
bra 1f
ENTRY(system_call)
SAVE_ALL
move #0x2000,%sr /* enable intrs again */
cmpl #NR_syscalls,%d0
jcc enosys
lea sys_call_table,%a0
lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */
movel %a0@(%d0),%d3
jeq enosys
1:
movel %sp,%d2 /* get thread_info pointer */
andl #-THREAD_SIZE,%d2 /* at start of kernel stack */
movel %d2,%a0
movel %a0@,%a1 /* save top of frame */
movel %sp,%a1@(TASK_THREAD+THREAD_ESP0)
btst #(TIF_SYSCALL_TRACE%8),%a0@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
bnes 1f
movel %d3,%a0
jbsr %a0@
movel %d0,%sp@(PT_OFF_D0) /* save the return value */
jra ret_from_exception
1:
movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */
movel %d2,PT_OFF_D0(%sp) /* on syscall entry */
subql #4,%sp
SAVE_SWITCH_STACK
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
movel %d3,%a0
jbsr %a0@
movel %d0,%sp@(PT_OFF_D0) /* save the return value */
subql #4,%sp /* dummy return address */
SAVE_SWITCH_STACK
jbsr syscall_trace_leave
ret_from_signal:
RESTORE_SWITCH_STACK
addql #4,%sp
ret_from_exception:
move #0x2700,%sr /* disable intrs */
btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */
jeq Luser_return /* if so, skip resched, signals */
#ifdef CONFIG_PREEMPT
movel %sp,%d1 /* get thread_info pointer */
andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
movel %d1,%a0
movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */
andl #(1<<TIF_NEED_RESCHED),%d1
jeq Lkernel_return
movel %a0@(TINFO_PREEMPT),%d1
cmpl #0,%d1
jne Lkernel_return
pea Lkernel_return
jmp preempt_schedule_irq /* preempt the kernel */
#endif
Lkernel_return:
moveml %sp@,%d1-%d5/%a0-%a2
lea %sp@(32),%sp /* space for 8 regs */
movel %sp@+,%d0
addql #4,%sp /* orig d0 */
addl %sp@+,%sp /* stk adj */
rte
Luser_return:
movel %sp,%d1 /* get thread_info pointer */
andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
movel %d1,%a0
movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */
jne Lwork_to_do /* still work to do */
Lreturn:
RESTORE_USER
Lwork_to_do:
movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */
move #0x2000,%sr /* enable intrs again */
btst #TIF_NEED_RESCHED,%d1
jne reschedule
/* GERG: do we need something here for TRACEing?? */
Lsignal_return:
subql #4,%sp /* dummy return address */
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jsr do_signal
addql #4,%sp
RESTORE_SWITCH_STACK
addql #4,%sp
jmp Luser_return
/*
* This is the generic interrupt handler (for all hardware interrupt
* sources). Calls up to high level code to do all the work.
*/
ENTRY(inthandler)
SAVE_ALL
moveq #-1,%d0
movel %d0,%sp@(PT_OFF_ORIG_D0)
movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
andl #0x03fc,%d0 /* mask out vector only */
movel %sp,%sp@- /* push regs arg */
lsrl #2,%d0 /* calculate real vector # */
movel %d0,%sp@- /* push vector number */
jbsr do_IRQ /* call high level irq handler */
lea %sp@(8),%sp /* pop args off stack */
bra ret_from_exception
/*
* Beware - when entering resume, prev (the current task) is
* in a0, next (the new task) is in a1, so don't change these
* registers until their contents are no longer needed.
*/
ENTRY(resume)
movew %sr,%d1 /* save current status */
movew %d1,%a0@(TASK_THREAD+THREAD_SR)
movel %a0,%d1 /* get prev thread in d1 */
SAVE_SWITCH_STACK
movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
RDUSP /* movel %usp,%a3 */
movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */
movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */
WRUSP /* movel %a3,%usp */
movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */
movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */
movew %d7,%sr
RESTORE_SWITCH_STACK
rts